"use strict"; test("basic functionality", () => { expect(isStrictMode()).toBeTrue(); (function () { expect(isStrictMode()).toBeTrue(); })(); (() => { expect(isStrictMode()).toBeTrue(); })(); (() => { "use strict"; expect(isStrictMode()).toBeTrue(); })(); function a() { expect(isStrictMode()).toBeTrue(); } a(); eval("expect(isStrictMode()).toBeTrue()"); });